Computer security covers all the processes and mechanisms by which digital equipment, information and services are protected from unintended or unauthorized access, change or destruction and the process of applying security measures to ensure confidentiality, integrity, and availability of data both in transit and at rest.[2]

A vulnerability is a system susceptibility or flaw, and an exploitable vulnerability is one for which at least one working attack exists. Many vulnerabilities are documented in the Common Vulnerabilities and Exposures (CVE) database and vulnerability management is the cyclical practice of identifying, classifying, remediating, and mitigating vulnerabilities.

To understand the techniques for securing a computer system, it is important to first understand the various types of "attacks" that can be made against it, and these threats can typically be classified into one of the categories in the sections below:

Denial of service attacks are designed to make a machine or network resource unavailable to its intended users. Attackers can deny service to individual victims, such as by deliberately entering a wrong password enough consecutive times to cause the victim account to be locked, or they may overload the capabilities of a machine or network and block all users at once.

An attack from a single IP address can be blocked by adding a new firewall rule, but many forms of Distributed denial of service (DDoS) attacks are possible, where the attack comes from a large number of points - and defending is much more difficult. Such attacks can originate from the zombie computers of a botnet, but a range of other techniques are possible including reflection and amplification attacks, where innocent systems are fooled into sending traffic to the victim.

Common consumer devices that can be used to transfer data surreptitiously.

An unauthorized user gaining physical access to a computer is often able to compromise security by making operating system modifications, installing software worms, keyloggers, or covert listening devices. They may be able to easily download data. Even when the system is protected by standard security measures, these may be able to be by passed by booting another operating system or tool from a CD-ROM or other bootable media. Disk encryption and Trusted Platform Module are designed to prevent these attacks.

Eavesdropping is the act of surreptitiously listening to a private conversation, typically between hosts on a network. For instance, programs such as Carnivore and NarusInsight have been used by the FBI and NSA to eavesdrop on the systems of internet service providers. Even machines that operate as a closed system (i.e., with no contact to the outside world) can be eavesdropped upon via monitoring the faint electro-magnetic transmissions generated by the hardware; TEMPEST is a specification by the NSA referring to these attacks.

An exploit is a software tool designed to take advantage of a flaw in a computer system. This frequently includes gaining control of a computer system, allowing privilege escalation, or creating a denial of service attack. The code from exploits is frequently reused in trojan horses and computer viruses. In some cases, a vulnerability can lie in certain programs' processing of a specific file type, such as a non-executable media file. Some security web sites maintain lists of currently known unpatched vulnerabilities found in common programs.

An indirect attack is an attack launched by a third-party computer. By using someone else's computer to launch an attack, it becomes far more difficult to track down the actual attacker. There have also been cases where attackers took advantage of public anonymizing systems, such as the Tor onion router system.

Web sites that accept or store credit card numbers and bank account information are prominent hacking targets, because of the potential for immediate financial gain from transferring money, making purchases, or selling the information on the black market. In-store payment systems and ATMs have also been tampered with in order to gather customer account data and PINs.

The aviation industry is very reliant on a series of complex system which could be attacked.[8] A simple power outage at one airport can cause repercussions worldwide,[9] much of the system relies on radio transmissions which could be disrupted, [10] and controlling aircraft over oceans is especially dangerous because radar surveillance only extends 175 to 225 miles offshore.[11] There is also potential for attack from within an aircraft.[12]

The consequences of a successful attack range from loss of confidentiality to loss of system integrity, which may lead to more serious concerns such as exfiltration of data, network and air traffic control outages, which in turn can lead to airport closures, loss of aircraft, loss of passenger life, damages on the ground and to transportation infrastructure. A successful attack on a military aviation system that controls munitions could have even more serious consequences.

Quantified Self devices, such as activity trackers, and mobile apps often collect personal information, such as heartbeat, diet, notes on activities (from exercise in public to sexual activities), and performance of bodily functions. Wifi, Bluetooth, and cell phone network devices can be used as attack vectors, and sensors might be remotely activated after a successful attack.[13]

Not all attacks are financially motivated however. Sony Pictures has been the target of two such attacks: one by activists in 2012 that took personal data on thousands of people;[17] and another in 2014 where the hackers appear to have taken data mainly to embarrass the company,[18] and also attempted to cripple the company by wiping workstations and servers.[19]

If access is gained to a car's internal controller area network, it is possible to disable the brakes and turn the steering wheel.[20] Computerized engine timing, cruise control, anti-lock brakes, seat belt tensioners, door locks, airbags and advanced driver assistance systems make these disruptions possible, and self-driving cars go even further. Connected cars may use wifi and bluetooth to communicate with onboard consumer devices, and the cell phone network to contact concierge and emergency assistance services or get navigational or entertainment information; each of these networks is a potential entry point for malware or an attacker.[20] Researchers in 2011 were even able to use a malicious compact disc in a car's stereo system as a successful attack vector,[21] and cars with built-in voice recognition or remote assistance features have onboard microphones which could be used for eavesdropping.

A 2015 report by U.S. Senator Edward Markey criticized manufacturers' security measures as inadequate, and also highlighted privacy concerns about driving, location, and diagnostic data being collected, which is vulnerable to abuse by both manufacturers and hackers.[22]

Local and regional government infrastructure such as traffic light controls, police and intelligence agency communications, personnel records and financial systems are also potential targets as they are now all largely computerized.

Serious financial damage has been caused by security breaches, but because there is no standard model for estimating the cost of an incident, the only data available is that which is made public by the organizations involved. “Several computer security consulting firms produce estimates of total worldwide losses attributable to virus and worm attacks and to hostile digital acts in general. The 2003 loss estimates by these firms range from $13 billion (worms and viruses only) to $226 billion (for all forms of covert attacks). The reliability of these estimates is often challenged; the underlying methodology is basically anecdotal.”[31]

However, reasonable estimates of the financial cost of security breaches can actually help organizations make rational investment decisions. According to the classic Gordon-Loeb Model analyzing the optimal investment level in information security, one can conclude that the amount a firm spends to protect information should generally be only a small fraction of the expected loss (i.e., the expected value of the loss resulting from a cyber/information security breach).[32]

A common part of threat modelling is to attempt to identify what might motivate an attack on the system, and who might be motivated to breach it. The level and detail of precautions will vary depending on the system to be secured. A home personal computer, bank and classified military network face very different threats, even when the underlying technologies in use are similar.

As with physical security, the motivations for breaches of computer security vary between attackers. Some are thrill-seekers or vandals, others are activists or criminals looking for financial gain. State-sponsored attackers are now common and well resourced, but started with amateurs such as Markus Hess who hacked for the KGB, as recounted by Clifford Stoll, in The Cuckoo's Egg.

In computer security a countermeasure is an action, device, procedure, or technique that reduces a threat, a vulnerability, or an attack by eliminating or preventing it, by minimizing the harm it can cause, or by discovering and reporting it so that corrective action can be taken.[34][35][36]

A state of computer "security" is the conceptual ideal, attained by the use of the three processes: threat prevention, detection, and response. These processes are based on various policies and system components, which include the following:

Firewalls are by far the most common prevention systems from a network security perspective as they can (if properly configured) shield access to internal network services, and block certain kinds of attacks through packet filtering. Firewalls can be both hardware- or software-based.

"Response" is necessarily defined by the assessed security requirements of an individual system and may cover the range from simple upgrade of protections to notification of legal authorities, counter-attacks, and the like. In some special cases, a complete destruction of the compromised system is favored, as it may happen that not all the compromised resources are detected.

Today, computer security comprises mainly "preventive" measures, like firewalls or an exit procedure. A firewall can be defined as a way of filtering network data between a host or a network and another network, such as the Internet, and can be implemented as software running on the machine, hooking into the network stack (or, in the case of most UNIX-based operating systems such as Linux, built into the operating system kernel) to provide real time filtering and blocking. Another implementation is a so-called physical firewall which consists of a separate machine filtering network traffic. Firewalls are common amongst machines that are permanently connected to the Internet.

However, relatively few organisations maintain computer systems with effective detection systems, and fewer still have organised response mechanisms in place. As result, as Reuters points out: “Companies for the first time report they are losing more through electronic theft of data than physical stealing of assets”.[37] The primary obstacle to effective eradication of cyber crime could be traced to excessive reliance on firewalls and other automated "detection" systems. Yet it is basic evidence gathering by using packet capture appliances that puts criminals behind bars.

Responding forcefully to attempted security breaches (in the manner that one would for attempted physical security breaches) is often very difficult for a variety of reasons:

Identifying attackers is difficult, as they are often in a different jurisdiction to the systems they attempt to breach, and operate through proxies, temporary anonymous dial-up accounts, wireless connections, and other anonymising procedures which make backtracing difficult and are often located in yet another jurisdiction. If they successfully breach security, they are often able to delete logs to cover their tracks.

The sheer number of attempted attacks is so large that organisations cannot spend time pursuing each attacker (a typical home user with a permanent (e.g., cable modem) connection will be attacked at least several times per day[citation needed], so more attractive targets could be presumed to see many more). Note however, that most of the sheer bulk of these attacks are made by automated vulnerability scanners and computer worms.

Law enforcement officers are often unfamiliar with information technology, and so lack the skills and interest in pursuing attackers. There are also budgetary constraints. It has been argued that the high cost of technology, such as DNA testing, and improved forensics mean less money for other kinds of law enforcement, so the overall rate of criminals not getting dealt with goes up as the cost of the technology increases. In addition, the identification of attackers across a network may require logs from various points in the network and in many countries, the release of these records to law enforcement (with the exception of being voluntarily surrendered by a network administrator or a system administrator) requires a search warrant and, depending on the circumstances, the legal proceedings required can be drawn out to the point where the records are either regularly destroyed, or the information is no longer relevant.

Computer code is regarded by some as a form of mathematics. It is theoretically possible to prove the correctness of certain classes of computer programs, though the feasibility of actually achieving this in large-scale practical systems is regarded as small by some with practical experience in the industry; see Bruce Schneier et al.

It is also possible to protect messages in transit (i.e., communications) by means of cryptography. One method of encryption—the one-time pad—is unbreakable when correctly used. This method was used by the Soviet Union during the Cold War, though flaws in their implementation allowed some cryptanalysis; see the Venona project. The method uses a matching pair of key-codes, securely distributed, which are used once-and-only-once to encode and decode a single message. For transmitted computer encryption this method is difficult to use properly (securely), and highly inconvenient as well. Other methods of encryption, while breakable in theory, are often virtually impossible to directly break by any means publicly known today. Breaking them requires some non-cryptographic input, such as a stolen key, stolen plaintext (at either end of the transmission), or some other extra cryptanalytic information.

Two factor authentication is a method for mitigating unauthorized access to a system or sensitive information. It requires “something you know”; a password or PIN, and “something you have”; a card, dongle, cellphone, or other piece of hardware. This increases security as an unauthorized person needs both of these to gain access.

Social engineering and direct computer access (physical) attacks can only be prevented by non-computer means, which can be difficult to enforce, relative to the sensitivity of the information. Even in a highly disciplined environment, such as in military organizations, social engineering attacks can still be difficult to foresee and prevent.

Trusting computer program code to behave securely has been pursued for decades. It has proven difficult to determine what code 'will never do.' Mathematical proofs are illusive in part because it is so difficult to define secure behavior even notionally, let alone mathematically. In practice, only a small fraction of computer program code is mathematically proven, or even goes through comprehensive information technology audits or inexpensive but extremely valuable computer security audits, so it is usually possible for a determined hacker to read, copy, alter or destroy data in well secured computers, albeit at the cost of great time and resources. Few attackers would audit applications for vulnerabilities just to attack a single specific system. It is possible to reduce an attacker's chances by keeping systems up to date, using a security scanner or/and hiring competent people responsible for security. The effects of data loss/damage can be reduced by careful backing up and insurance. However software-based strategies have not yet been discovered for protecting computers from adequately funded, dedicated malicious attacks.

Security by design, or alternately secure by design, means that the software has been designed from the ground up to be secure. In this case, security is considered as a main feature.

Some of the techniques in this approach include:

The principle of least privilege, where each part of the system has only the privileges that are needed for its function. That way even if an attacker gains access to that part, they have only limited access to the whole system.

Defense in depth, where the design is such that more than one subsystem needs to be violated to compromise the integrity of the system and the information it holds.

Default secure settings, and design to "fail secure" rather than "fail insecure" (see fail-safe for the equivalent in safety engineering). Ideally, a secure system should require a deliberate, conscious, knowledgeable and free decision on the part of legitimate authorities in order to make it insecure.

Audit trails tracking system activity, so that when a security breach occurs, the mechanism and extent of the breach can be determined. Storing audit trails remotely, where they can only be appended to, can keep intruders from covering their tracks.

The Open Security Architecture organization defines IT security architecture as "the design artifacts that describe how the security controls (security countermeasures) are positioned, and how they relate to the overall information technology architecture. These controls serve the purpose to maintain the system's quality attributes: confidentiality, integrity, availability, accountability and assurance services".[38]

Techopedia defines security architecture as "a unified security design that addresses the necessities and potential risks involved in a certain scenario or environment. It also specifies when and where to apply security controls. The design process is generally reproducible." The key attributes of security architecture are:[39]

the relationship of different components and how they depend on each other.

the determination of controls based on risk assessment, good practice, finances, and legal matters.

While hardware may be a source of insecurity, such as with microchip vulnerabilities maliciously introduced during the manufacturing process,[40][41] hardware-based or assisted computer security also offers an alternative to software-only computer security. Using devices and methods such as dongles, trusted platform modules, intrusion-aware cases, drive locks, disabling USB ports, and mobile-enabled access may be considered more secure due to the physical access (or sophisticated backdoor access) required in order to be compromised. Each of these is covered in more detail below.

USB dongles are typically used in software licensing schemes to unlock software capabilities,[42] but they can also be seen as a way to prevent unauthorized access to a computer or other device's software. The dongle, or key, essentially creates a secure encrypted tunnel between the software application and the key. The principle is that an encryption scheme on the dongle, such as Advanced Encryption Standard (AES) provides a stronger measure of security, since it is harder to hack and replicate the dongle than to simply copy the native software to another machine and use it. Another security application for dongles is to use them for accessing web-based content such as cloud software or Virtual Private Networks (VPNs).[43] In addition, a USB dongle can be configured to lock or unlock a computer.[44]

Trusted platform modules (TPMs) secure devices by integrating cryptographic capabilities onto access devices, through the use of microprocessors, or so-called computers-on-a-chip. TPMs used in conjunction with server-side software offer a way to detect and authenticate hardware devices, preventing unauthorized network and data access.[45]

Computer case intrusion detection refers to a push-button switch which is triggered when a computer case is opened. The firmware or BIOS is programmed to show an alert to the operator when the computer is booted up the next time.

Disabling USB ports is a security option for preventing unauthorized and malicious access to an otherwise secure computer. Infected USB dongles connected to a network from a computer inside the firewall are considered by Network World as the most common hardware threat facing computer networks.[48]

Mobile-enabled access devices are growing in popularity due to the ubiquitous nature of cell phones. Built-in capabilities such as Bluetooth, the newer Bluetooth low energy (LE), Near field communication (NFC) on non-iOS devices and biometric validation such as thumb print readers, as well as QR code reader software designed for mobile devices, offer new, secure ways for mobile phones to connect to access control systems. These control systems provide computer security and can also be used for controlling access to secure buildings.[49]

One use of the term "computer security" refers to technology that is used to implement secure operating systems. Much of this technology is based on science developed in the 1980s and used to produce what may be some of the most impenetrable operating systems ever. Though still valid, the technology is in limited use today, primarily because it imposes some changes to system management and also because it is not widely understood. Such ultra-strong secure operating systems are based on operating system kernel technology that can guarantee that certain security policies are absolutely enforced in an operating environment. An example of such a Computer security policy is the Bell-LaPadula model. The strategy is based on a coupling of special microprocessor hardware features, often involving the memory management unit, to a special correctly implemented operating system kernel. This forms the foundation for a secure operating system which, if certain critical parts are designed and implemented correctly, can ensure the absolute impossibility of penetration by hostile elements. This capability is enabled because the configuration not only imposes a security policy, but in theory completely protects itself from corruption. Ordinary operating systems, on the other hand, lack the features that assure this maximal level of security. The design methodology to produce such secure systems is precise, deterministic and logical.

Systems designed with such methodology represent the state of the art[clarification needed] of computer security although products using such security are not widely known. In sharp contrast to most kinds of software, they meet specifications with verifiable certainty comparable to specifications for size, weight and power. Secure operating systems designed this way are used primarily to protect national security information, military secrets, and the data of international financial institutions. These are very powerful security tools and very few secure operating systems have been certified at the highest level (Orange Book A-1) to operate over the range of "Top Secret" to "unclassified" (including Honeywell SCOMP, USAF SACDIN, NSA Blacker and Boeing MLS LAN). The assurance of security depends not only on the soundness of the design strategy, but also on the assurance of correctness of the implementation, and therefore there are degrees of security strength defined for COMPUSEC. The Common Criteria quantifies security strength of products in terms of two components, security functionality and assurance level (such as EAL levels), and these are specified in a Protection Profile for requirements and a Security Target for product descriptions. None of these ultra-high assurance secure general purpose operating systems have been produced for decades or certified under Common Criteria.

In USA parlance, the term High Assurance usually suggests the system has the right security functions that are implemented robustly enough to protect DoD and DoE classified information. Medium assurance suggests it can protect less valuable information, such as income tax information. Secure operating systems designed to meet medium robustness levels of security functionality and assurance have seen wider use within both government and commercial markets. Medium robust systems may provide the same security functions as high assurance secure operating systems but do so at a lower assurance level (such as Common Criteria levels EAL4 or EAL5). Lower levels mean we can be less certain that the security functions are implemented flawlessly, and therefore less dependable. These systems are found in use on web servers, guards, database servers, and management hosts and are used not only to protect the data stored on these systems but also to provide a high level of protection for network connections and routing services.

If the operating environment is not based on a secure operating system capable of maintaining a domain for its own execution, and capable of protecting application code from malicious subversion, and capable of protecting the system from subverted code, then high degrees of security are understandably not possible. While such secure operating systems are possible and have been implemented, most commercial systems fall in a 'low security' category because they rely on features not supported by secure operating systems (like portability, and others). In low security operating environments, applications must be relied on to participate in their own protection. There are 'best effort' secure coding practices that can be followed to make an application more resistant to malicious subversion.

Some common languages such as C and C++ are vulnerable to all of these defects (see Seacord, "Secure Coding in C and C++").[50] Other languages, such as Java, are more resistant to some of these defects, but are still prone to code/command injection and other software defects which facilitate subversion.

Another bad coding practice occurs when an object is deleted during normal operation yet the program neglects to update any of the associated memory pointers, potentially causing system instability when that location is referenced again. This is called dangling pointer, and the first known exploit for this particular problem was presented in July 2007. Before this publication the problem was known but considered to be academic and not practically exploitable.[51]

Unfortunately, there is no theoretical model of "secure coding" practices, nor is one practically achievable, insofar as the code (ideally, read-only) and data (generally read/write) generally tends to have some form of defect.

Within computer systems, two of many security models capable of enforcing privilege separation are access control lists (ACLs) and capability-based security. Using ACLs to confine programs has been proven to be insecure in many situations, such as if the host computer can be tricked into indirectly allowing restricted file access, an issue known as the confused deputy problem. It has also been shown that the promise of ACLs of giving access to an object to only one person can never be guaranteed in practice. Both of these problems are resolved by capabilities. This does not mean practical flaws exist in all ACL-based systems, but only that the designers of certain utilities must take responsibility to ensure that they do not introduce flaws.[citation needed]

Capabilities have been mostly restricted to research operating systems, while commercial OSs still use ACLs. Capabilities can, however, also be implemented at the language level, leading to a style of programming that is essentially a refinement of standard object-oriented design. An open source project in the area is the E language.

The most secure computers are those not connected to the Internet and shielded from any interference. In the real world, the most secure systems are operating systems where security is not an add-on.

In 1988, only 60,000 computers were connected to the Internet, and most were mainframes, minicomputers and professional workstations. On November 2, 1988, many started to slow down, because they were running a malicious code that demanded processor time and that spread itself to other computers - the first internet "computer worm".[52] The software was traced back to 23 year old Cornell University graduate student Robert Tappan Morris, Jr. who said 'he wanted to count how many machines were connected to the Internet'.[52]

In 1994, over a hundred intrusions were made by unidentified crackers into the Rome Laboratory, the US Air Force's main command and research facility. Using trojan horses, hackers were able to obtain unrestricted access to Rome's networking systems and remove traces of their activities. The intruders were able to obtain classified files, such as air tasking order systems data and furthermore able to penetrate connected networks of National Aeronautics and Space Administration's Goddard Space Flight Center, Wright-Patterson Air Force Base, some Defense contractors, and other private sector organizations, by posing as a trusted Rome center user.[53]

In early 2013, massive breaches of computer security by the NSA were revealed, including deliberately inserting a backdoor in a NIST standard for encryption[61] and tapping the links between Google's data centres.[62] These were disclosed by NSA contractor Edward Snowden.[63]

In 2013 and 2014, a Russian/Ukrainian hacking ring known as "Rescator" broke into Target Corporation computers in 2013, stealing roughly 40 million credit cards,[64] and then Home Depot computers in 2014, stealing between 53 and 56 million credit card numbers.[65] Warnings were delivered at both corporations, but ignored; physical security breaches using self checkout machines are believed to have played a large role. “The malware utilized is absolutely unsophisticated and uninteresting,” says Jim Walter, director of threat intelligence operations at security technology company McAfee - meaning that the heists could have easily been stopped by existing antivirus software had administrators responded to the warnings. The size of the thefts has resulted in major attention from state and Federal United States authorities and the investigation is ongoing.

Conflict of laws in cyberspace[66] has become a major cause of concern for computer security community. Some of the main challenges and complaints about the antivirus industry are the lack of global web regulations, a global base of common rules to judge, and eventually punish, cyber crimes and cyber criminals. There is no global cyber law[67] and cybersecurity treaty[68] that can be invoked for enforcing global cybersecurity issues.

International legal issues of cyber attacks[69] are complicated in nature.[70] Even if an antivirus firm locates the cyber criminal behind the creation of a particular virus or piece of malware or form of cyber attack, often the local authorities cannot take action due to lack of laws under which to prosecute.[71][72] Authorship attribution for cyber crimes and cyber attacks is a major problem for all law enforcement agencies.[73]

"[Computer viruses] switch from one country to another, from one jurisdiction to another — moving around the world, using the fact that we don't have the capability to globally police operations like this. So the Internet is as if someone [had] given free plane tickets to all the online criminals of the world."[71] Use of dynamic DNS, fast flux and bullet proof servers have added own complexities to this situation.[74]

The role of the government is to make regulations to force companies and organizations to protect their systems, infrastructure and information from any cyber attacks, but also to protect its own national infrastructure such as the national power-grid.[citation needed]

The question of whether the government should intervene or not in the regulation of the cyberspace is a very polemical one. Indeed, for as long as it has existed and by definition, the cyberspace is a virtual space free of any government intervention. Where everyone agree that an improvement on cybersecurity is more than vital, is the government the best actor to solve this issue? Many government officials and experts think that the government should step in and that there is a crucial need for regulation, mainly due to the failure of the private sector to solve efficiently the cybersecurity problem. R. Clarke said during a panel discussion at the RSA Security Conference in San Francisco, he believes that the "industry only responds when you threaten regulation. If industry doesn't respond (to the threat), you have to follow through."[75] On the other hand, executives from the private sector agree that improvements are necessary but think that the government intervention would affect their ability to innovate efficiently.

The "Cybersecurity Act of 2010 - S. 773" was introduced first in the Senate on April 1, 2009 by Senator Jay Rockefeller (D-WV), Senator Evan Bayh (D-IN), Senator Barbara Mikulski (D-MD), Senator Bill Nelson (D-FL), and Senator Olympia Snowe (R-ME). The revised version was approved on March 24, 2009.[76]
The main objective of the bill is to increase collaboration between the public and the private sector on the issue of cybersecurity. But also

"to ensure the continued free flow of commerce within the United States and with its global trading partners through secure cyber communications, to provide for the continued development and exploitation of the Internet and intranet communications for such purposes, to provide for the development of a cadre of information technology specialists to improve and maintain effective cybersecurity defenses against disruption, and for other purposes."[76]

The act also wants to instate new higher standards, processes, technologies and protocols to ensure the security of the "critical infrastructure".

On March 25, 2010, Representative Yvette Clarke (D-NY) introduced the "International Cybercrime Reporting and Cooperation Act - H.R.4962"[77] in the House of Representatives; the bill, co-sponsored by seven other representatives (among whom only one Republican), was referred to three House committees.[78] The bill seeks to make sure that the administration keeps Congress informed on information infrastructure, cybercrime, and end-user protection worldwide. It also "directs the President to give priority for assistance to improve legal, judicial, and enforcement capabilities with respect to cybercrime to countries with low information and communications technology levels of development or utilization in their critical infrastructure, telecommunications systems, and financial industries"[78] as well as to develop an action plan and an annual compliance assessment for countries of "cyber concern".[78]

On June 19, 2010, United States SenatorJoe Lieberman (I-CT) introduced a bill called "Protecting Cyberspace as a National Asset Act of 2010 - S.3480"[79] which he co-wrote with Senator Susan Collins (R-ME) and Senator Thomas Carper (D-DE). If signed into law, this controversial bill, which the American media dubbed the "Kill switch bill", would grant the President emergency powers over the Internet. However, all three co-authors of the bill issued a statement claiming that instead, the bill "[narrowed] existing broad Presidential authority to take over telecommunications networks".[80]

On May 12, 2011, the White House sent Congress a proposed cybersecurity law designed to force companies to do more to fend off cyberattacks, a threat that has been reinforced by recent reports about vulnerabilities in systems used in power and water utilities.[81]

In October 2009, the Department of Homeland Security opened the National Cybersecurity and Communications Integration Center. The center brings together government organizations responsible for protecting computer networks and networked infrastructure.[85]

In addition to its own specific duties, the FBI participates alongside non-profit organizations such as InfraGard, "...an association of businesses, academic institutions, state and local law enforcement agencies, and other participants dedicated to sharing information and intelligence to prevent hostile acts against the United States".[88][89]

The United States Cyber Command, also known as USCYBERCOM, is tasked with the defense of specified Department of Defense information networks and "ensure US/Allied freedom of action in cyberspace and deny the same to our adversaries."[91] It has no role in the protection of civilian networks.[92][93]

The U.S. Federal Communications Commission's role in cybersecurity is to strengthen the protection of critical communications infrastructure, to assist in maintaining the reliability of networks during disasters, to aid in swift recovery after, and to ensure that first responders have access to effective communications services.[94]

The Council of Europe helps protect societies worldwide from the threat of cybercrime through the Convention on Cybercrime and its Protocol on Xenophobia and Racism, the Cybercrime Convention Committee (T-CY) and the Project on Cybercrime.[98]

The purpose of the Messaging Anti-Abuse Working Group (MAAWG) is to bring the messaging industry together to work collaboratively and to successfully address the various forms of messaging abuse, such as spam, viruses, denial-of-service attacks and other messaging exploitations. To accomplish this, MAAWG develops initiatives in the three areas necessary to resolve the messaging abuse problem: industry collaboration, technology, and public policy.[99]France Telecom, Facebook, AT&T, Apple, Cisco, Sprint are some of the members of the MAAWG.[99]

The objective of ENISA is to improve network and information security in the European Union. The agency has to contribute to the development of a culture of network and information security for the benefit of the citizens, consumers, enterprises and public sector organisations of the European Union, and consequently will contribute to the smooth functioning of the EU Internal Market.

Following cyberattacks in the first half of 2013, whereby government, news-media, television station, and bank websites were compromised, the national government committed to the training of 5,000 new cybersecurity experts by 2017. The South Korean government blamed its northern counterpart on these attacks, as well as incidents that occurred in 2009, 2011, and 2012, but Pyongyang denies the accusations.[100]

Seoul, March 7, 2011 - South Korean police have contacted 35 countries to ask for cooperation in tracing the origin of a massive cyber attack on the Web sites of key government and financial institutions, amid a nationwide cybersecurity alert issued against further threats. The Web sites of about 30 key South Korean government agencies and financial institutions came under a so-called distributed denial-of-service (DDoS) attack for two days from Friday, with about 50,000 "zombie" computers infected with a virus seeking simultaneous access to selected sites and swamping them with traffic. As soon as the copies of overseas servers are obtained, the cyber investigation unit will analyse the data to track down the origin of the attacks made from countries, including the United States, Russia, Italy and Israel, the NPA noted.[101]

In late September 2013, a computer-security competition jointly sponsored by the defense ministry and the National Intelligence Service was announced. The winners will be announced on September 29, 2013 and will share a total prize pool of 80 million won (US$74,000).[100]

India has no specific law for dealing with cybersecurity related issues.[102] Some provisions for cybersecurity have been incorporated into rules framed under the Information Technology Act 2000 but they are grossly insufficient. Further, the National Cyber Security Policy 2013 has remained ineffective and non-implementable until now.[103] The cybersecurity trends and developments in India 2013 have listed the shortcomings of Indian cybersecurity policy in general and Indian cybersecurity initiatives in particular.[104] Indian cybersecurity policy has also failed to protect civil liberties of Indians including privacy rights.[105] Civil liberties protection in cyberspace has been blatantly ignored by Indian government and e-surveillance projects have been kept intact by the Narendra Modi government.[106] As a result Indian cybersecurity efforts are inadequate and not up to the mark. There is also no legal obligation for cybersecurity breach disclosures in India as well.[107]

However, the Indian Companies Act 2013 has introduced cyber law[108] and cyber security obligations[109] on the part of Indian directors. Cyber security obligations for e-commerce business in India have also been recognised recently.[110]

On October 3, 2010, Public Safety Canada unveiled Canada’s Cyber Security Strategy, following a Speech from the Throne commitment to boost the security of Canadian cyberspace.[111][112] The aim of the strategy is to strengthen Canada’s “cyber systems and critical infrastructure sectors, support economic growth and protect Canadians as they connect to each other and to the world.”[113] Three main pillars define the strategy: securing government systems, partnering to secure vital cyber systems outside the federal government, and helping Canadians to be secure online.[113] The strategy involves multiple departments and agencies across the Government of Canada.[114] The Cyber Incident Management Framework for Canada outlines these responsibilities, and provides a plan for coordinated response between government and other partners in the event of a cyber incident.[115] The Action Plan 2010-2015 for Canada's Cyber Security Strategy outlines the ongoing implementation of the strategy.[116]

Public Safety Canada’s Canadian Cyber Incident Response Centre (CCIRC) is responsible for mitigating and responding to threats to Canada’s critical infrastructure and cyber systems. The CCIRC provides support to mitigate cyber threats, technical support to respond and recover from targeted cyber attacks, and provides online tools for members of Canada’s critical infrastructure sectors.[117] The CCIRC posts regular cyber security bulletins on the Public Safety Canada website.[118] The CCIRC also operates an online reporting tool where individuals and organizations can report a cyber incident.[119] Canada's Cyber Security Strategy is part of a larger, integrated approach to critical infrastructure protection, and functions as a counterpart document to the National Strategy and Action Plan for Critical Infrastructure.[114]

On September 27, 2010, Public Safety Canada partnered with STOP.THINK.CONNECT, a coalition of non-profit, private sector, and government organizations dedicated to informing the general public on how to protect themselves online.[120] On February 4, 2014, the Government of Canada launched the Cyber Security Cooperation Program.[121] The program is a $1.5 million five-year initiative aimed at improving Canada’s cyber systems through grants and contributions to projects in support of this objective.[122] Public Safety Canada aims to begin an evaluation of Canada's Cyber Security Strategy in early 2015.[114] Public Safety Canada administers and routinely updates the GetCyberSafe portal for Canadian citizens, and carries out Cyber Security Awareness Month during October.[123]

Here are the main computer emergency response teams around the world. Every country have their own team to protect network security. February 27, 2014, the Chinese network security and information technology leadership team is established. The leadership team will focus on national security and long-term development, co-ordination of major issues related to network security and information technology economic, political, cultural, social, and military and other fields of research to develop network security and information technology strategy, planning and major macroeconomic policy promote national network security and information technology law, and constantly enhance security capabilities.

CSIRTs in Europe collaborate in the TERENA task force TF-CSIRT. TERENA's Trusted Introducer service provides an accreditation and certification scheme for CSIRTs in Europe. A full list of known CSIRTs in Europe is available from the Trusted Introducer website.

Cybersecurity is becoming increasingly important as more information and technology is being made available on cyberspace. There is growing concern among governments that cyberspace will become the next theatre of warfare. As Mark Clayton from the Christian Science Monitor described in an article titled “The New Cyber Arms Race”:

In the future, wars will not just be fought by soldiers with guns or with planes that drop bombs. They will also be fought with the click of a mouse a half a world away that unleashes carefully weaponized computer programs that disrupt or destroy critical industries like utilities, transportation, communications, and energy. Such attacks could also disable military networks that control the movement of troops, the path of jet fighters, the command and control of warships.[124]

This has led to new terms such as cyberwarfare and cyberterrorism. More and more critical infrastructure is being controlled via computer programs that, while increasing efficiency, exposes new vulnerabilities. The test will be to see if governments and corporations that control critical systems such as energy, communications and other information will be able to prevent attacks before they occur. As Jay Cross, the chief scientist of the Internet Time Group, remarked, “Connectedness begets vulnerability.”[125]

Cyber Security is a fast-growing[126] field of IT concerned with reducing organizations' risk of hack or data breach. Commercial, government and non-governmental all employ cybersecurity professional, but the use of the term "cybersecurity" is government job descriptions is more prevalent than in non-government job descriptions, in part due to government "cybersecurity" initiatives (as opposed to corporation's "IT security" initiatives) and the establishment of government institutions like the US Cyber Command and the UK Defence Cyber Operations Group.[127]

Analyzes and assesses vulnerabilities in the infrastructure (software, hardware, networks), investigates available tools and countermeasures to remedy the detected vulnerabilities, and recommends solutions and best practices. Analyzes and assesses damage to the data/infrastructure as a result of security incidents, examines available recovery tools and processes, and recommends solutions. Tests for compliance with security policies and procedures. May assist in the creation, implementation, and/or management of security solutions.

Security Engineer

Performs security monitoring, security and data/logs analysis, and forensic analysis, to detect security incidents, and mounts incident response. Investigates and utilizes new technologies and processes to enhance security capabilities and implement improvements. May also review code or perform other security engineering methodologies.

Security Architect

Designs a security system or major components of a security system, and may head a security design team building a new security system.

Security Administrator

Installs and manages organization-wide security systems. May also take on some of the tasks of a security analyst in smaller organizations.

Chief Information Security Officer

A high-level management position responsible for the entire information security division/staff. The position may include hands-on technical work.

Security Consultant/Specialist/Intelligence

Broad titles that encompass any one or all of the other roles/titles, tasked with protecting computers, networks, software, data, and/or information systems against viruses, worms, spyware, malware, intrusion detection, unauthorized access, denial-of-service attacks, and an ever increasing list of attacks by hackers acting as individuals or as part of organized crime or foreign governments.

Student programs are also available to people interested in beginning a career in cybersecurity.[129][130] Meanwhile, a flexible and effective option for information security professionals of all experience levels to keep studying is online security training, including webcasts.[131][132][133]

The following terms used with regards to engineering secure systems are explained below.

Access authorization restricts access to a computer to group of users through the use of authentication systems. These systems can protect either the whole computer – such as through an interactive login screen – or individual services, such as an FTP server. There are many methods for identifying and authenticating users, such as passwords, identification cards, and, more recently, smart cards and biometric systems.

Applications with known security flaws should not be run. Either leave it turned off until it can be patched or otherwise fixed, or delete it and replace it with some other application. Publicly known flaws are the main entry used by worms to automatically break into a system and then spread to other systems connected to it. The security website Secunia provides a search tool for unpatched known flaws in popular products.

Authentication techniques can be used to ensure that communication end-points are who they say they are.

Automated theorem proving and other verification tools can enable critical algorithms and code used in secure systems to be mathematically proven to meet their specifications.

Backups are a way of securing information; they are another copy of all the important computer files kept in another location. These files are kept on hard disks, CD-Rs, CD-RWs, tapes and more recently on the cloud. Suggested locations for backups are a fireproof, waterproof, and heat proof safe, or in a separate, offsite location than that in which the original files are contained. Some individuals and companies also keep their backups in safe deposit boxes inside bank vaults. There is also a fourth option, which involves using one of the file hosting services that backs up files over the Internet for both business and individuals, known as the cloud.

Backups are also important for reasons other than security. Natural disasters, such as earthquakes, hurricanes, or tornadoes, may strike the building where the computer is located. The building can be on fire, or an explosion may occur. There needs to be a recent backup at an alternate secure location, in case of such kind of disaster. Further, it is recommended that the alternate location be placed where the same disaster would not affect both locations. Examples of alternate disaster recovery sites being compromised by the same disaster that affected the primary site include having had a primary site in World Trade Center I and the recovery site in 7 World Trade Center, both of which were destroyed in the 9/11 attack, and having one's primary site and recovery site in the same coastal region, which leads to both being vulnerable to hurricane damage (for example, primary site in New Orleans and recovery site in Jefferson Parish, both of which were hit by Hurricane Katrina in 2005). The backup media should be moved between the geographic sites in a secure manner, in order to prevent them from being stolen.

Endpoint security software helps networks to prevent exfiltration (data theft) and virus infection at network entry points made vulnerable by the prevalence of potentially infected portable computing devices, such as laptops and mobile devices, and external storage devices, such as USB drives.[136]

Firewalls are an important method for control and security on the Internet and other networks. A network firewall can be a communications processor, typically a router, or a dedicated server, along with firewall software. A firewall serves as a gatekeeper system that protects a company's intranets and other computer networks from intrusion by providing a filter and safe transfer point for access to and from the Internet and other networks. It screens all network traffic for proper passwords or other security codes and only allows authorized transmission in and out of the network. Firewalls can deter, but not completely prevent, unauthorized access (hacking) into computer networks; they can also provide some protection from online intrusion.

Honey pots are computers that are either intentionally or unintentionally left vulnerable to attack by crackers. They can be used to catch crackers or fix vulnerabilities.

Intrusion-detection systems can scan a network for people that are on the network but who should not be there or are doing things that they should not be doing, for example trying a lot of passwords to gain access to the network.

A microkernel is the near-minimum amount of software that can provide the mechanisms to implement an operating system. It is used solely to provide very low-level, very precisely defined machine code upon which an operating system can be developed. A simple example is the early '90s GEMSOS (Gemini Computers), which provided extremely low-level machine code, such as "segment" management, atop which an operating system could be built. The theory (in the case of "segments") was that—rather than have the operating system itself worry about mandatory access separation by means of military-style labeling—it is safer if a low-level, independently scrutinized module can be charged solely with the management of individually labeled segments, be they memory "segments" or file system "segments" or executable text "segments." If software below the visibility of the operating system is (as in this case) charged with labeling, there is no theoretically viable means for a clever hacker to subvert the labeling scheme, since the operating system per se does not provide mechanisms for interfering with labeling: the operating system is, essentially, a client (an "application," arguably) atop the microkernel and, as such, subject to its restrictions.

Pinging The ping application can be used by potential crackers to find if an IP address is reachable. If a cracker finds a computer, they can try a port scan to detect and attack services on that computer.

Social engineering awareness keeps employees aware of the dangers of social engineering and/or having a policy in place to prevent social engineering can reduce successful breaches of the network and servers.